A method for tracking a moving vehicle includes detecting the vehicle by acquiring a series of temporal related image frames. In an initial frame, the detecting includes locating a reference feature representative of a vehicle. The method further includes setting the reference feature as a full-size template. The method includes tracking the vehicle by searching a current frame for features matching the full-size template and at least one scaled template. The tracking further includes setting as an updated template one of the full-size and scaled templates closest matching the feature. The method includes repeating the tracking using the updated template for each next frame in the series.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for tracking a moving vehicle, the method comprising: detecting a vehicle, the detecting including: acquiring a series of temporal related image frames, and in an initial frame, locating a reference feature representative of a vehicle; setting the reference feature as a full-size template; tracking the vehicle, the tracking including: searching a current frame for a feature matching the full-size template, searching the current frame for a feature matching at least one scaled template, setting as an updated template one of the full-size and scaled templates closest matching the feature; and repeating the tracking using the updated template for each next frame in the series.
2. The method of claim 1 further comprising: using the tracking, computing a distance that the feature moves between select frames in the series using a location of the feature in the select frames; and, computing a speed using the distance.
3. The method of claim 1 , wherein the feature includes at least one portion of a license plate.
4. The method of claim 1 further comprising: scaling the full-size template by a predetermined amount to generate the scaled template.
5. The method of claim 4 , wherein the predetermined scaling amount is dynamic amount using at least one of camera calibration data, a current location of the feature, an average vehicle speed of a current traffic scene being monitored, and a scaling value from a previously tracked feature.
6. The method of claim 1 , wherein the searching the current frame for a feature matching the full size template includes: computing a first correlation number for describing a similarity between the feature and the full-size template; and, storing the first correlation number and a location of the feature in the current frame; wherein the searching the current frame for a feature matching the at least one scaled template includes: computing a second correlation number for describing a similarity between feature and the scaled template; and, storing the second correlation number and the location of the feature in the current frame.
7. The method of claim 6 , wherein the setting the updated template includes: comparing the first and second correlation numbers; determining a higher one of the first and second correlation numbers; setting as the updated template the one of the full-size template and scaled template corresponding to the higher correlation number.
8. The method of claim 1 further comprising: cropping a region around the feature; and, setting the cropped region as the full size template.
9. A computer program product comprising non-transitory computer-readable recording media which encodes instructions for performing the method of claim 1 .
10. A system for tracking a moving vehicle, the system comprising: a tracking device comprising memory which stores instructions for performing the method of claim 1 and a processor, in communication with the memory for executing the instructions.
11. A system for tracking a moving vehicle, the system comprising: a vehicle tracking device, including: an image capture module adapted to acquire a series of temporal related image frames a vehicle detection module adapted to: in an initial frame, locate a reference feature representative of a moving object; a vehicle tracking module adapted to: set the reference feature as a full-size template, search a current frame for a feature matching the full-size template, search the current frame for a feature matching at least one scaled template, set as an updated template one of the full-size and scaled templates closest matching the feature, and repeat the tracking using the updated template for each next frame in the series; and, a processor adapted to implement the modules.
12. The system of claim 11 further comprising a speed computation module adapted to: using the tracking, compute a distance that the feature moves between a first frame and a last frame that the vehicle is detected in the series; compute a speed using the distance.
13. The system of claim 11 , wherein the feature includes at least one portion of a license plate.
14. The system of claim 11 , wherein the vehicle tracking module is further adapted to: scale the full-size template a predetermined amount to generate the scaled template.
15. The system of claim 14 , wherein the predetermined amount is a dynamic amount being computed using one of camera calibration data, a current location of the feature, an average vehicle speed of a current traffic scene being monitored, and a scaling value from a previously tracked feature.
16. The system of claim 12 , wherein the vehicle tracking module is further adapted to: compute a first correlation number for describing a similarity between the feature and the full-size template; and, compute a second correlation number for describing a similarity between feature and the scaled template; and, store the first and second correlation numbers with a location of the feature in the current frame.
17. The system of claim 16 , wherein the vehicle tracking module is further adapted to: compare the first and second correlation numbers; determine a higher one of the first and second correlation numbers; set as the updated template the one of the full-size template and scaled template corresponding to the higher correlation number.
18. The system of claim 12 , wherein the vehicle detection module is further adapted to: crop a region around the feature; and, set the cropped region as the full size template.
19. The system of claim 12 further comprising a video capture device adapted to capture the temporal related image frames and transmit the frames to the vehicle detection module.
20. A method for tracking a moving vehicle, the method comprising: detecting a vehicle, the detecting including: acquiring a series of temporal related image frames, and in an initial frame, locating a reference feature representative of a moving object; setting the reference feature as a full-size template; scaling the full-size template predetermined amounts to generate multiple scaled templates; tracking the moving object, the tracking including: searching the current frame for a feature matching the scaled templates, computing a correlation number for describing a similarity between the detected feature and each of the full-size template and scaled templates; setting as an updated template one of the full-size template and scaled templates corresponding to highest correlation number; and storing a location of the feature in the current frame associated with the highest correlation number; and, repeating the tracking for each next frame in the series.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 12, 2012
March 3, 2015
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